<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    
    .content{
        height: 200px;
        background: pink;
        padding: 0 200px;
        float: left;
        width: 100%;
        padding: 0 200px;
    }
    .left{
        height: 200px;
        width: 200px;
        background: purple;
        float: left;
      margin-left: -100%;
    }
    .right{
        height: 200px;
        width: 200px;
        background: royalblue;
        float: left;
    }
  </style>
</head>
<body>
  <div class="box">
    <div class="content">content</div>
    <div class="left">left</div>
    <div class="right">right</div>
  </div>
</body>
</html>
